This application claims priority to co-pending Swiss application No. 00615/14, filed on Apr. 14, 2014.
The invention relates to a device for measuring the moisture in die casting molds as well as to a method for measuring the moisture in die casting molds.
To permit removal of the finished casting after solidification from the mold in die casting the cavity of the mold is sprayed with a release agent. Such release agents are preferably mixed with water in the ratio of 1:100 before being sprayed. When the release agent mixed with water is sprayed hot, all of the water evaporates ideally leaving just a thin film of release agent achieving release of the casting and preventing the metal sticking to the mold. In addition to functioning as a medium carrying the release agent the water can also have the further function of cooling the casting mold. One of the problems involved in using a release agent mixed with water is that, for one thing, enough water must be used to ensure a full spraying of the walls of the cavity whilst ensuring sufficient cooling of the mold. For another, the amount of water must not be so much that there is a risk of the water not being fully evaporated, resulting in inclusions of water or water vapor in the casting on completion of casting, which, of course, is unwanted and resulting in quality deficiencies in the finished casting. This is why it would be an advantage when an indication could be made as to whether the water has more or less evaporated or whether water residues remain in the mold.
One obvious variant for measuring the moisture content in die cast molds would involve arranging one or more sensors within the die cast mold by means of which the moisture content can be measured. But because the die cast mold, depending on the metal to be casted may be hot to a few hundred to more than a thousand degrees, such a solution is impracticable since hardly any sensor is able to furnish precise results in measurement under such harsh conditions over any lengthy period of time, especially since the molten metal could also damage and/or pollute the sensor.